For longitudinal field studies involving substance abusers, successfully tracking, locating, and following up with a representative sample of subjects is a challenge. One meta-analysis of 85 longitudinal studies of substance abuse clients found that nearly one-third of subjects were lost to attrition within 36 months (Hansen, Tobler, & Graham, 1990). This poses a significant threat to the validity of findings in the substance abuse (and related) fields, as follow-up rates below 80% have been shown to produce dramatically biased estimates of drug use and crime (Nemes et al., 2002). The purpose of this Phase II Small Business Technology Transfer (STTR) proposal is to conduct a randomized field test of the rechargeable incentive card (RIC) system developed in Phase I, and to execute a detailed plan to commercialize the finalized set of products and services. The RIC System involves an on-the-spot issued debit card linked to an account in which researchers can immediately transfer funds following a follow-up contact (whether this involves telephone or in-person interviews, mail-in surveys, or provision of biological samples). The card also contains a toll-free number that subjects can use to call (as often as once a month) to notify the researchers of changes in their locator/contact information. This, too, results in an automatic transfer of funds to the subjects' RIC System account. This technology was developed though a close collaboration between the Calance Corporation and the UCLA Integrated Substance Abuse Programs (ISAP). In Phase II, this same collaborative will finalize the RIC System, commercialize it, and test its impact on follow-up rates and staff time devoted to tracking and locating subjects, using a sample of substance abusers (N=300) enrolled in three outpatient treatment programs in the Los Angeles area. The RIC System could be employed in studies involving medication, education, employment, and panel studies in many research areas, but the application holds particular promise in the field of substance abuse research which often involves itinerant, hard-to-track subjects-many of whom have criminal justice histories.